This study attempted to examine whether emotional empathy mediates the relationship between pathological narcissism and mentalization failure, and to verify whether emotional perception clarity regulates this mediating effect. To this end, data were collected through an online survey of 399 adults aged 19 to 60, and the mediating effect, moderating effect, and moderated mediating effect were analyzed. For research purposes, the Pathological Narcissism Inventory (PNI), the Mentalization Questionnaire (MZQ), the Empathy Ability Scale, and the Trait Meta-Mood Scale (TMMS) were used. The results of the study are as follows. First, as a result of correlation analysis between variables, it was found that there was a significant correlation between pathological narcissism, emotional empathy, mentalization failure, and emotional perception clarity. Second, the mediating effect of emotional empathy was significant in the relationship between pathological narcissism and mentalization failure. Third, the relationship between emotional empathy and mentalization failure was controlled by emotional perception clarity. Fourth, it was found that the mediating effect of emotional empathy on the relationship between pathological narcissism and mentalization failure was moderated by emotional perception clarity. This study revealed that the path that pathological narcissism leads to mentalization failure through the mediation of emotional empathy depends on the level of individual's emotional perception clarity. It was suggested that these results could be used as basic data to help therapeutic intervention by using them in counseling and psychotherapy scenes.